1. Field of the Invention
The present invention relates in general to read/write methods for CD-MRW (Mount Rainier ReWrite), and more particularly, to read/write methods which split a read-block or write-packet range into several sub-ranges to reduce the size of DRAM buffer required for the read/write procedures of CD-MRW.
2. Description of the Prior Art
Over the past few years, storage media have rapidly increased in capacity due to increasing demand for storing tremendous amounts of information. Of all various kinds of storage media, optical discs are a low-cost, small-size, low-error-rate, long-storage-time, and high-density storage medium and are the most promising storage medium for the future. Optical discs mainly fall into two categories: compact disc (CD) and digital versatile disc (DVD). Compact discs further fall into several categories such as: CD-Interactive (CD-I), CD-Recordable (CD-R), CD-Erasable (CD-E), CD-Read Only Memory (CD-ROM), CD-Plus, and CD-Rewritable (CD-RW), and CR-MRW.
Based on these various kinds of CDs, some optical disc standards have been created such as a Red Book for storage standards of music and image frames, a Book for storage standards of digital data, a Green Book for storage standards of animation, an Orange Book for storage standards of rewritable discs, and a Blue Book for storage standards of hybrid data formats. Thereafter, manufacturers can fabricate various kinds of optical discs based on the abovementioned standards.
Among the different kinds of optical discs, the CD-MRW discis able to support defect management provided by multi-media command (MMC) set modifications. According to the specifications of CD-MRW, a data area (DA) is composed of 136 packets and a spare area (SA) is composed of 8 packets. Furthermore, each packet is composed of 32 data blocks, a link block, and a plurality of run-in and run-out blocks. A block is the smallest reading unit and a packet is the smallest writing unit. When a DA contains a defect block, data in the packet of an SA associated with the defect block is read to revise the corresponding block and then write the whole packet back to the SA. Therefore, the advantage of defect management is undermined by the complexity of the read/write procedures.